This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. SPECIMEN PREPARATION, PRESERVATION AND STAINING TECHNOLOGIES FOR MAPPING PROTEINS, CELLULAR COMPLEXES, PATHWAYS AND THE SUPRAMOLECULAR ORGANIZATION OF TISSUES USING MULTIPLE LABELS AND MULTISCALE IMAGING. Our efforts in this area focused on continuing to develop technologies to enable imaging of proteins and macromolecular complexes using multiple labels and multiscale microscopies. These approaches include (1) expanding our repertoire of fluorescent compounds used for multiscale imaging;(2) combining high-pressure freezing/freeze-substitution with molecular labeling approaches to further enhance preservation of ultrastructure;(3) adapting metal chelating derivatives of diaminobenzidine to enable simultaneous multi-protein EM labeling using electron energy loss spectroscopy (EELS), and other detection methods;(4) and exploring the feasibility of cathodoluminescence (CL) imaging using quantum dots, nanophosphors and fluorescent proteins.